What is Union ?
Union is noun 1. (trade) union an organisation which represents workers who are its members in discussions with em- ployers about wages and conditions of em- ployment The staff are all members of a union or they are (trade) union members. The union called a meeting to discuss the company’s takeover by a German company. 2. the state of being joined together We support the union of these various groups un- der one umbrella organisation. 3. a group of countries or independent states which are linked into a federation The union between England and Scotland is over 300 years old. 4. the United States of America The Presi- dent will give his State of the Union message in January. 5. marriage Their union will be celebrated on 1st November.
source: Easier English, Student Dictionary Upper Intermediate Level